General questions about attic fans in an old building?

Question

I own a restaurant that's in a150 year old building & its hard to keep cool in the summer and warm in the winter.

(My landlord is an idiot and super-cheap so he's not a good reference for me financially or to answer any questions!)

1. How can I even find out if an attic fan exists? (there's an opening into the attic from the kitchen area where you can access the attic, but assuming I'm not going to crawl along the rafters but instead just stand on a ladder & look with a flashlight, where would the attic fan be if there IS one?
2. If there IS one, are they usually controlled by an accessible switch, or would it be turned on somewhere on the fan itself?
3. If there ISN'T one, is this something that I can buy and have a friend install, or is it more complicated than that?
4. If I need a professional, who does this kind of thing?a handyman? or HVAC pro?
5. What kind of price am i looking at for the fan itself? the installation (if needed)?

thanks SO MUCH for any advice!

Orak-thanks so much for the info! Couple of things..we DO have an exhaust fan "hood" over the stove, grill, etc. and you are right that is code. I'm talking more about an attic fan to circulate the air and cool it down. You are absolutely right about the make up air...which has always been a problem for us. Our hood guy that installed the hood was awful and basically installed in and left, only for us to find out year later that we were sucking up all the air and heat with the hood fan. WE do have blown insulation that we just put in last summer....
thanks!

Answer 1

Jeniusvi:

I've read your question, and I also read Oraks answer. His response was well thought out and fairly comprehensive - IF you are in need of a kitchen exhust fan and corresponding make-up air and combustion air set up.

But as I read you question I wasn;t sure that's what you were asking about . It sounded to me like you were asking more along the lines of venting hot air our of the attic space in the summer, and making the attic warmer in the winter.

If that is what you are after, thenI think you are looking at a much simpler solution, and certainly a much less costly issue to deal with.

Let's address something that you might be thinking about - if you can vent the attic - and get it cooled down - can you suck hot air out of the kitchen in the summer time up thru the attic & out thru the roof vents? Answer: NO. I'm beting you need to maintain a 1 hour fire barrier between the kitchen and the attic. (Just wanted to get that out of the way)

OK. How can you tell of your attic is vented? Does your building have a "flat roof"or a gabled or ridge roof like on a house? If you have a Gabled roof , or a ridge roof look at the sloped roof area to see if you see roof vents. There are 3 types you are lloking for. Ridge vent: A ridge vent looks like a "cap" on top of the ridge or peak of the roof. Box vents: Box vents are almost square rectangular vents about 14" x 16" x 4" that sit on the slope of the roof about 2' - 4' down from the ridge - in a horizontal line - say 6 - 12 in a row. Turbines" Turbines are in most cases non-motor driven whirly birds that sort of look like the way your wife wraps her hair up in a towel after she steps out of the shower. They are silber sheet metal, ans the wind spins the "blades" which suck the air out of the attic, People usually paint them to match the roof. If there were a dozen box vents on a sloped roof, then you'd probably only need 4 turbines to replace them.

Then there are gable end Vents. Go to the "Side" of the Building where the Roof peaks in the form of a triangle. A gable end vent wouls be a louvered inset in the top 2feet of this triangle - on both sides of the building - to allow for "flow thru ventiliation" The ventilation requirments for most attics is 1/300.

If you have a sloped roof, you may also have overhanging soffits, there could be soffit vents in these as well, - but unlikely in a building 150 years old.

If you have a flat roof, the vents are usuanll sections of stove pipe 6" - 8" in diameter with China Hat covers over the pipes , set up on legs to allow air out, and keep rain & snow from getting in.

It is doubtfull that there is any insulation in the attic, and while putting in a vapor barrier and insulation will help to keep your Kitchen warmer in the winter and cooler in the summer, it may lead to problems in the future with mold growth in the ceiling, and buckling / warping of the bottom chords of your roof rafters. Unless you were to build in a lower insulated drop ceiling. - and install the VB in that dropped ceiling. You can then still blow in about 38 inches of fiberglass insulation in the attic space - and install 8" of polyisocyanurate insulation over a 6 mil. VB over a 8" sttel stud framed new ceiling tied off to a black iron frame, and sheath the ceiling in two layers of 1/2: type "C" or two layers 5/8 " Type X sheetrock, taped and finsihed, and painted with epoxy primer & 2 coats of epoxy paint. Install surface mtd light fixtures.

Cost? Depends on the size of the kitchen, and what you need for venting, and new celing . Get 3 estimates. But first hire an A/E firm to do a set of 6 drawing sheets and an outline spec for you so that your bidders are all bidding apples to apples, and everything is covered. (then get an estimate done from a contractor or a Professional Cost estimator, (and allow yourself a minimum 8% contingency allowance, ( after all its a 150 year old building - never know what you might run into)

At this point I strongly recommend that you hire a construction pahse Owner's rep. to oversee tne construction - for conformance to the Contract Documents, to see that the proper materials are used, and to make suire that the job stays on schedule, and he OK's Partial Payment Requests, etc. See if you can get your Architect to do this on a hourly not to exceed lump sum amount. Or maybe you have a friend in the Construction Business who can help you out?

A contingency is a "slush fund" part oif your construction loan that you control, that you hope you don't have to spend - but it's there "just in case". Let's say that You get your drawings done for $ 1,500.00. You get a construction extimated done for $ 400.00. You have 20 sets of drawings made and post them in the local builders exchange for as many contractors to bid as you can get, (the more competition the better). Cost of printing $ 250.00. The bid period runs 2 weeks You get a $ 15.00 deposit on each bid set that a contractor picks up, which you will return after the bids are in - providing he returns the full set back to you unmarked, and in good condition. You issue 1 addendum to answer contractors questions and clarify some issues during the bnid period, - for Builders exchange to send out for you to the bidders. $ 10.00.

You get bids back, and then sit down with the low bidder abd go over his bid to make sure he's accounted for everything, and hasn't included things in his bid that are unnecessary, - to make sure you have the lowest price possible.

THen work out the Contract, pay attention to start date and end date. There's lots more but this should giuve you a litle idea of what it takes. Good luck!

Answer 2

Howdy:

Most kitchens (that have stoves/ovens) should have an exhaust fan by code, does your kitchen? (your codes may be different in your area of course).

Can you get up on the roof? There should be a vent on the roof if you have a fan now.

You can look in the attic, there should be an opening in your kitchen, perhaps some duct work and a fan upstairs. The power switch can be just about any place. Some are on the breaker panel, some on the unit, some in the kitchen. With a building that old, there is no way to know where it might be without looking around. If you find a fan, try tracing the electrical wiring to see where it goes. It may have a switch right at the fan, or along the wires.

In this part of the country, kitchens have a vent fan on the roof, and a "make-up air" unit nearby to bring in cooler air. Some times the make up air units are evaporative coolers, that is, they have water dripping onto filters and air goes across these wet filters and into the kitchen area. The theory is, the water absorbs heat from the air prior to going into the kitchen. Make up air is needed so that an exhaust fan does not create a vacuum in your kitchen and it actually moves more air so that more heat is removed from the kitchen.

Contact three HVAC contractors in your area and ask if they give free estimates, or if they deduct the estimate cost from the install. The estimate should include the cost of all electrical installation, ducting, mechanical. You could also ask if they will handle the permitting & final inspection. If you do have an exhaust fan installed, you will need to have some type of make-up air or static air vent installed. Unless your handy worker is familiar with all of this, you will have fewer headaches with a pro team.

If the kitchen is cool in the winter, you don't have any insulation in the attic. This may also cut down on your summer heat gain if you don't do a lot of cooking in the kitchen.

If you sink a lot of money improving your landlord's property, will he reimburse you, reduce your rent, or kick you out and rent to a higher-paying customer after you've upgraded his property? If there is a comperable location nearby available, perhaps it may be time to investigate moving, or get a price so that you can use this as a tool for negotiating who will pay for the upgrades.

Answer 3

On attic fans--we used to have one, and they are great. If the old one is in the attic, you might be able to get an electrician to replace the motor. But you know to use it, you have to open lots of windows, right? Then it pulls in the air, making it chilly even in the heat of the summer. But it is loud. Ours had the louver section in a central hallway, with the switch to turn it on nearby. Ours in the attic had some kind of papery (like cardboard) thing tenting the louvers as well. I don't think they are all that complicated, but you'd have to find the specifications to put one together. A HVAC guy would probably not know anything about them.

I think the price probably would run a couple hundred at the most for the fan, installation a couple of hours of an electrician or handyman's time. But I do not know if they are even still made, as they are considered pretty obsolete.

Answer 4

Simple. An attic may or may not have a switch down below. Many are controlled by a temperature sensing switch.
If you don't see one up there, measure the attic and determine the approximate cubic feet....look up the formulas, an important factor in choosing a fan. A fan is rated by the cubic feet per minute that it moves (CFM). The more air removed, the cooler it will be. For example, a 500 CFM exhaust fan will remove the hot air from a 2,500 cubic foot attic every 5 minutes....a 1,000 CFM fan removes it every 2 1/2 minutes.
A competent handyman should be ok for this, but back yourself up seeking advice from a major retailor like Home Depot or Lowes. Another great source is an industrial supply company very familiar with this; Graingers. They are nationwide (find them online) and the right department sales advisor will help you on the phone. I don't work for them, honest. I have purchased and installed dozens of very large exhaust fans for hot factories from them (like 15,000 CFM and bigger).

Answer 5

Calculate the sqare footage of your attic area ( a rough estimate will do, doesn't have to be exact). Next - determine that you have some type of soffit or "eave" vents installed. Many older homes didn't have them, if you don't, for this to work you have to have them installed. Purchase a power roof vent sized for the square footage of your attic area (depending on how big it is, you may need 2). Any competent roofer or small contractor can install the power roof vents. You'll need a receptacle installed in the attic area to power the roof vent(s). Power vents come with a thermostat which can be set to energize the vents at a pre-determined temperature (most are set at 90 degrees, which is fine). What you are doing is drawing air from the soffit venting up into the attic area and expelling it via the power vents, which effectively cools the attic. Any good home improvements store (Lowes, Home Depot) will carry power vents in different sizes to accommodate different square footage requirements.