fredag 31 oktober 2014

Light density

Light density decoupling material provides an air space separation between the
pipe or duct and the exterior barrier cladding. This decoupler material is
commonly specified to be light density fiber glass with a minimum of 1” (25 mm)
thickness. Thicknesses greater than 1” offer improved capabilities up to a
practical upper limit of approximately 2” to 3” (50 to 75 mm). The decoupler
material needs to be light and porous as it is the air trapped within the material
which serves the purpose of acoustically separating the wall of the pipe or duct
from the exterior barrier cladding. As an analogy, it is the air space between two
(2) panes of glass which provides the insulation properties of a window. Care
should be taken in the event that a pipe carrying steam or hot water is to be
wrapped to ensure that the temperature insulation capabilities of the decoupler
satisfy the project requirements.

torsdag 30 oktober 2014


The canopy hood needs to be designed and operated
to ensure effective removal of cooking fumes. It needs
to be a suitable size and have enough extraction to
minimise fume spillage into the kitchen. There should be
a canopy hood for every appliance and other sources
generating fumes and heat. The canopy hood should
be as close as possible to the source, taking into
account the work requirements.
The airflow into the canopy should be uniform and
constant, and meet the appropriate design flow for the
appliances and room ventilation rate. Canopies and
ductwork need to be constructed from non-combustible
material and made so they discourage accumulations
of dirt or grease, and condensation. There should be
suitable access to the ductwork, to allow regular cleaning
to prevent accumulation of fat etc. Grease filters need to
be readily removable for cleaning/replacement.

onsdag 29 oktober 2014

Replacement air

Replacement air
The ventilation system design should take into account
the need to replace extracted air. Mechanical and/or
natural means can provide make-up air, but it should
be fresh and unadulterated from the outside.
In smaller kitchens, there may be sufficient
replacement air drawn in naturally via ventilation grilles
in walls, doors or windows.
Where air is drawn in naturally, some means of control
over pest entry is usually needed. A fine mesh grille
will restrict the ventilation, and a larger grille area
can compensate. However, for larger installations, a
mechanical system using a fan and filter is more suitable.
The ‘clean air’ should not be taken from ‘dirty’ areas,
eg waste storage, smoking areas etc. The make-up air
should not impair the performance of flues serving gas

tisdag 28 oktober 2014


The extraction rate is best calculated from the
information supplied with the appliances. It should also
take account of air change rates required for kitchens.
Where canopies are not used, eg where extraction is
through ventilated ceilings, consult a competent heating
and ventilation engineer to calculate the appropriate
ventilation rates.
The design should avoid draughts where the kitchen is
subdivided (eg wash-ups, vegetable preparations).
Mechanical ventilation systems should be maintained
in efficient working order in accordance with the
manufacturer’s/installer’s instructions.

måndag 27 oktober 2014

what type of specific

what type of specific
equipment you will
In generic terms a
typical equipment
package to inspect,
clean and
decontaminate HVAC
systems will include:
• Vacuum collection
system – puts
ductwork under
negative pressure
• Agitation tools –
used to dislodge
accumulated dirt,
debris and
contaminates. This
includes power
brushing systems,

söndag 26 oktober 2014

Portable electric

Portable electric
vacuum collection
systems offer the most
flexibility in that you
can clean virtually any
type (residential,
apartments, condos,
light commercial and
commercial) of
building with them.
You bring these
collectors into the
building and position
them where you can
be the most
productive. You zone
off (divide up) the
HVAC system to
achieve the suction
you need to clean.
These units operate
on 110 or 220 volt, 50
or 60 Hz., and have
HEPA filtration.

lördag 25 oktober 2014

portable gas vacuum

portable gas vacuum
collection systems are
less expensive than
truck mounted units,
but like them, they sit
outside and you bring
in the large 50’ to 100’
long suction hose to
connect to the
ductwork. Depending
on the system you
may or may not have
to zone off the HVAC
system to achieve the
suction you need to
effectiviely clean.
You are limited to
cleaning residential
and one or two story
commercial buildings.

fredag 24 oktober 2014

The large truck

The large truck
mounted units offer
lots of suction so you
typically do not have
to zone off the HVAC
system. These units
sit outside and a large
50’ to 100’ long
suction hose is
brought into the home
or building and
connected to the
ductwork. You are
limited to cleaning
residential and one or
two story commercial
buildings with the
truck mounted units.
These units are also
the most expensive
and require the most
• Trailer mounted and

torsdag 23 oktober 2014

Direct Replacement of Exhaust Air Limitation

Measure 1: Direct Replacement of Exhaust Air Limitation The economic justification for this measure was made by comparing equipment first cost and energy cost differences between an exhaust-only hood system versus an equivalently performing short-circuit hood system for a 10’ section of cooking line. An exhaust-only hood provides adequate capture and containment in this hood section with 1,500 cfm of exhaust air. The replacement air is assumed to come from the room in both cases. An equivalently performing 10’ short-circuit hood would have to exhaust 3,000 cfm with 1,500 cfm of replacement air being directly injected into the hood and the remaining 1,500 cfm coming from the room.  The basis of comparison used the costs of the hoods, the cost of the exhaust fans, and the cost of the addition makeup air unit required for the short-circuit system. The energy comparison used the brake horsepower difference between the exhaust and makeup air fans. The difference in brake horsepower was then converted to KW and multiplied by 15-year hourly energy cost data.  The systems were assumed to operate from 11 am to 11 pm everyday to simulate a typical restaurant serving lunch and dinner. Climate Zone 12 was used as the source of the energy costs but the energy savings are not associated with climate and would apply to all climate zones. Other metrics like the amount of ductwork, fire-proofing insulation could also be compared but since there is no component of a short- circuit hood system that is smaller and thereby costs less over an exhaust-only hood system, the comparison is limited to this small set of essential equipment to justify the costs.  Equipment cost data has been provided by a kitchen hood vendor.

Effective kitchen ventilation systems

Effective kitchen ventilation systems
The objectives of an effective kitchen ventilation
system are to:
■ remove cooking fumes at source, ie at the appliance;
■ remove excess hot air and bring in cool, clean
air, so the working environment is comfortable.
Inadequate ventilation can cause stress,
contributing to unsafe systems of work and high
staff turnover;
■ make sure that the air movement in the kitchen
does not cause discomfort, eg from strong
■ provide enough air for complete combustion at
fired appliances, and prevent the risk of carbon
monoxide accumulating;
■ be easy to clean, avoiding build-up of fat residues
and blocked air inlets, which lead to loss of
efficiency and increased risk of fire;
■ be quiet and vibration free.

onsdag 22 oktober 2014

Type I Exhaust Hood Airflow Limitations

Measure 2: Type I Exhaust Hood Airflow Limitations The cost justification for this measure compares two kitchen hood designs of equal capture and containment performance. The Base Case uses an unlisted hood sized to meet prescribed code minimum or ASHRAE Standard 154 exhaust rates. The Proposed Case uses a listed hood sized to meet 30% better than ASHRAE Standard 154 Rates listed in Table 1.
3.3 Measure 3: Makeup and Transfer Air Requirements The economic justification for this measure was completed by comparing the energy and energy costs required to condition a kitchen over a range of transfer air percentages of kitchen exhaust air. These costs were graphed to illustrate the relative energy cost savings of using the maximum transfer air

tisdag 21 oktober 2014

Measure 4

Measure 4: Commercial Kitchen System Efficiency Options The cost effectiveness of demand control ventilation kitchen systems has been studied by the utility, Southern California Edison (SCE), who commissioned a study in 2009 which reviewed five commercial kitchen installations using DCV. The installations were all based on the Melink Intelli- hood system and included installation costs and exhaust fan energy savings only. Air conditioning energy savings were not studied. The installations represented different sectors of the market: smaller quick service restaurants and larger hotel and resort kitchens. The results of their study are used here to justify the cost effectiveness of DCV system as a design option for this measure.

måndag 20 oktober 2014

Statewide Energy Savings

Statewide Energy Savings  The statewide energy savings associated with the proposed measures were calculated by multiplying the per unit estimate with the statewide estimate of new construction in 2014. The new construction forecast was derived from a study Southern California Edison’s Food Service Technology Center performed (SCE 2009

söndag 19 oktober 2014

4.2 Measure 2:

4.2 Measure 2: Type I Exhaust Hood Airflow Limitations Equipment and electrical costs of each case were compared. Only the hoods, exhaust fans, and makeup fans were used. Similar comparisons could include differences in duct sizes, diffuser size and counts, and the conditioning energy. As these additional comparisons would reveal the same differences as the values used, they were not included. Table 4below compares the equipment costs between an exhaust and makeup air system using an unlisted hood versus a listed hood. The unlisted 10’ canopy wall hood for heavy duty used requires an exhaust rate of 550 cfm per linear foot of the leading edge of the hood. A similar listed hood requires an exhaust rate of 385 cfm per linear foot. The hood costs per the vendor we consulted are the same. The explanation for this is that the hoods have similar amounts of sheet metal and require similar amounts of labor to construct. The only difference between them is the vendor’s expense to test their hood designs for listing. It was explained that most cataloged commercial hoods are listed which creates cost competition so there is no economic benefit to pursue an unlisted hood. The exhaust fans and makeup air fans cost data reflect fans sized for the specific hood cfm. In the scenario developed, there is a $5,676 difference in the equipment. Table 5 below compares the power and electrical costs to exhaust and makeup the different air rates. The electrical costs assumed 5,400 hours of operation a year and an average electrical rate of $0.15 per kilowatt-hour. The annual electrical cost difference between the systems is $1,523. The data shows that listed hoods cost the same as unlisted hoods but the fans cost more for system with the higher exhaust rate. Subsequent, the energy costs are also more for the system with the higher exhaust rate.

lördag 18 oktober 2014

A scenario

Measure 3: Makeup and Transfer Air Requirements A scenario describing a typical kitchen/dining room design was developed as the basis of comparison for the range of transfer air ratios in different climates. The scenario uses the following assumptions:  1,000 square foot commercial kitchen  10,000 cfm exhaust hood  Cooling supply airflow: 2,000 cfm or 80% of the exhaust cfm   Supply air temperature was  to 55°F  Space temperature setpoint, return air, and transfer air temperatures were set to 70°F  Cooling load of 9.5 w/sf  $0.12/Kwh Electrical Rate  $1/therm Gas Rate  0.0005 KW/cfm fan energy use  1 Kw/ton cooling equipment efficiency  0.70 thermal efficiency for gas heating equipment  Hour of operation: 6am to 10pm daily for a total of 5,838 hours per year.

fredag 17 oktober 2014

A spreadsheet

A spreadsheet was created that used these assumptions to calculate the costs associated with fan energy, cooling energy, and heating energy over a year using 5°F bin weather data. The weather data was filtered to only the number of hours in each temperature bin within the 6am to 10pm hours of operation. The annual energy costs were tabulated over the range of available transfer air percentages. Low transfer air percentages represent higher amounts outside makeup air that must be conditioned. High transfer air represents lower amounts of outside makeup air.

torsdag 16 oktober 2014

Condensation, Dripping, and Frost

Condensation, Dripping, and Frost

Problems arise during cold temperatures when warm, moist air from the home reaches the attic, is not vented to the outside, and it lingers in the cooler and drier attic. As the dew point is reached, water vapor held in the warmer air condenses on cold attic surfaces — building components, such as rafters, trusses, and roof sheathing. See figure 2. In the winter, during low temperatures, the condensed moisture can appear as frost.

Measure 1: Direct Replacement of Exhaust Air Limitation

Measure 1: Direct Replacement of Exhaust Air Limitation The equipment cost for the measure case based on an exhaust-only hood system described in the test scenario is $1,604 less than an equivalently performing short-circuit hood system in the base case when comparing the hoods, exhaust fans, and makeup air units. The energy cost difference between the two systems over 15 years using the 2011 energy data for CTZ 12 is $6,435. As demonstrated, there is no performance or economic benefit associated with short-circuit hood systems when compared to exhaust-only hood systems.  The proposal allows 10% direct replacement to allow hood manufacturers to employ different capture and containment strategies that resemble short-circuit hoods but do not have the performance deficiencies of short-circuit hoods.  Systems that use less than 10% direct replacement include the Halton Capture Jet, which has been tested by the PG&E Food Service Technology Center and shown to provide equal or better C&C compared to an exhaust-only hood with the exhaust flow rate.

onsdag 15 oktober 2014

If too much water

If too much water soaks into the insulation, it can become compressed and lose its insulating power. We have even seen ice crystals that formed throughout fiberglass insulation. When the insulation is in this condition, it loses some of its insulating power. This leads to greater heat loss, colder rooms, a greater demand on the furnace, and to higher utility bills.

måndag 13 oktober 2014

Frost collection on the underside of a roof.

Frost collection on the underside of a roof.
Frost collection on the underside of a roof.
This moisture causes damage in two ways. First, moisture condensing on the roof’s structural building components will soak into the wood. This can lead to wood rot and the deterioration of roofing materials. Second, moisture eventually will drip onto the building components below.

söndag 12 oktober 2014

Unvented moistur

Unvented moisture in cold weather results in compromised roof structure, lower energy efficiency and damaged building components below the attic.

During cold weather, proper ventilation helps prevent moisture from condensing on the roof, the structural members, the insulation, and the framing and sheetrock below the attic.

lördag 11 oktober 2014

Rust, Warping of Roof Decking,

Rust, Warping of Roof Decking, and Deterioration of Roof System

In a nature, rust can structure on metal segments like nails and clasp, which can in the end debilitate and fizzle. Distorted top decking can happen after unreasonable dampness leaks into the top decking and breaks up the cements that hold them together. The decking twists or droops between the rafters. Disintegration of the top framework, including the underlayment and shingles can be created by inordinate hotness and dampness not being vented out of the loft.

fredag 10 oktober 2014

Buildup or Mold

Buildup or Mold

Shape and Mildew developing on the underside of a top.

Shape and Mildew developing on the underside of a top.

A damp environment is the ideal spot for mold or mold to develop. Mold development in lofts causes a wellbeing danger for the individuals living in the home, and can result in crumbling of the inside building segments.

Fitting ventilation lessens dampness develop and minimizes the opportunity for mold to develop, which delays the life of your home's building segments and decreases wellbeing effects

torsdag 9 oktober 2014

Air pollution sources

Air pollution sources
Another step the Agency recommends is identifying potential sources of air pollution within the home. Taking a survey of your home and identifying where heating systems are located, how chemicals are stored and how well-ventilated individual rooms are can provide an avenue for improved air quality, even if those areas aren’t the actual cause for poor air quality.
If you’ve taken the above steps and still want to undertake testing for individual air pollutants, contact your local health department for guidance on how to begin evaluating your home’s air quality with the help of professionals.


Dripping moisture also can penetrate into the attic floor and, eventually, into the ceiling below. If this occurs, the top-floor ceilings may exhibit water stains and paint damage. When this type of damage is visible, that is a good chance that the framing material behind the sheetrock has also been damaged by moisture.

onsdag 8 oktober 2014

Cancer risks from radon

Cancer risks from radon
However, due to its strong correlation to lung cancer, it’s strongly recommended that homeowners test their homes for radon, especially when moving into a new home or occupying a home where no radon mitigation system exists. Homeowners concerned about carbon monoxide can purchase carbon monoxide detectors that signal when unhealthy amounts of the gas build up.
The EPA says that health problems can be one of first indicators of an air quality problem, especially if the appearance of symptoms coincides with a recent move to a new residence, a recent remodeling project or a recent application of pesticides. It recommends consulting with your health provider or local health department to help determine if poor air quality may be the cause of health symptoms.

tisdag 7 oktober 2014

Should you test your air?

Should you test your air?

If you’re concerned about the quality of your indoor air, you should examine a number of issues before turning to costly indoor air quality testing. Because there is not one comprehensive indoor air quality test, hiring a firm or purchasing a multiple test kits prior to eliminating possible sources of poor indoor air quality can be a costly and time-consuming exercise.

måndag 6 oktober 2014

Controlling secondhand smoke

Controlling secondhand smoke
The most effective way to prevent secondhand smoke from contributing to poor indoor air quality is to never smoke indoors.  If any of your home occupants smoke indoors, ask them to do so outside. The same goes for visitors who may smoke.

söndag 5 oktober 2014


One of the easiest indoor air quality factors to control is the negative effects of smoking tobacco products indoors. Not only does smoking indoors produce a foul odor that can linger in upholstery, clothing and carpeting, secondhand smoke can cause cancer, serious respiratory illnesses and aggravate asthma. Children are especially vulnerable to secondhand smoke.

lördag 4 oktober 2014

Volatile organic compounds (VOCs) from household items

Volatile organic compounds (VOCs) from household items
According to the EPA, volatile organic compounds or VOCs are chemicals that can be commonly found in household products such as cleaning products, paints, chemical strippers, waxes and pesticides. Other in-home products that can produce VOCs that contribute to poor indoor air quality include floor coverings, furniture, electronic equipment, air fresheners and dry-cleaned clothing.
VOCs from household items can be especially hard to pinpoint as the cause of poor indoor air quality because the VOCs naturally evaporate into the air when the products are used or stored.

fredag 3 oktober 2014

Controlling pollutants from combustion devices

Controlling pollutants from combustion devices
The most effective way to control indoor air pollution from combustion or heating devices is to make sure they’re used and maintained properly. The EPA recommends that you make sure there’s adequate ventilation in any area where a fuel-burning or heating device is being operated. If and when you use a heating or fuel-based device, make sure that it’s properly installed and up-to-date on maintenance and repairs.

torsdag 2 oktober 2014



How do you get heat from cold air?

Air/water heat pumps utilise the heat energy of the outside air.
The heat pumps are designed for outside placement and transform an existing radiator system into an excellent, complete heating system. 
Heat pump technology is actually based on a very simple, well-known principle. It works in a similar way to any domestic refrigerator, using a vapour compression cycle.
The main components in the heat pump are the compressor, the expansion valve and two heat exchangers (an evaporator and a condenser).
A fan draws the outdoor air into the heat pump where it meets the evaporator. This is connected in a closed system containing a refrigerant that can turn into gas at very low temperatures. When the outdoor air hits the evaporator the refrigerant will turn into gas.
Then, using a compressor, the gas reaches a high enough temperature to be transferred in the condensor to the house’s heating system. At the same time the refrigerant reverts to liquid form, ready to turn into gas once more and to collect new heat.
Using an inverter-driven heat pump compressor, the system can be regulated so that heat output matches the exact capacity required at any given time. This means the heat pump will only consume the exact energy needed, making it highly efficient.
In the summer, the refrigeration circuit is capable of operating in reverse to provide cooling on demand.
Air/water heat pumps utilise the heat energy of the outside air.
The heat pumps are designed for outside placement and transform
an existing radiator system into an excellent, complete heating system.

onsdag 1 oktober 2014

Why throw out old energy when you can recycle it instead?

Why throw out old energy when you can recycle it instead?

An heat recovery ventilation unit is basically an energy recycling system. It collects energy from the warm inside air as it leaves your home via the ventilation system, and re-uses it to heat up fresh incoming air.
If you’re building a new house or developing new apartments, now’s the perfect time to take advantage of NIBE’s energy efficient heating technology. Install a heat recovery ventilation unit and you can enjoy a healthy, oxygen-rich atmosphere inside your home, at the same time as reducing your electricity consumption.