Ductless minisplit system for a one-story bungalow
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We are renovating a 1235 sq ft one-story bungalow and are located in zone 3A on the coast where it is very hot and humid in the summer months and the winters are mild. We have insulated the entire house with spray foam. Windows are single pane with storm windows on the outside. There are 7 rooms made up of an open livingroom/kitchen area in the middle flanked by two small bedrooms and a small bath on either end.
We have been researching the feasibility of a mini-split system versus a traditional hvac system. So far, the prices we have been quoted range from $5000 for the traditional, up to over $12,000 for the mini-split. We would welcome any suggestions/advice as to whether this is a good application for the mini-split; how many zones we would need, and if those costs are reasonable for that size house? We have researched the different brands and there seems to be pros and cons with each one.
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Replies
1235 sq ft
7 rooms
How is this possible?
(PS: go with traditional, or DIY https://www.acwholesalers.com/Ductless-Air-Conditioner-Wall-Mounted-Air-Conditioners/cat1028.ac?mainCat= You are being taken for a ride. )
C.K. Lafayette,
If I were in your shoes, I would certainly choose the $5,000 system over the $12,000 system.
You haven't given us much information, however.
1. You haven't told us whether anyone has performed a Manual J load calculation (a heating load calculation and a cooling load calculation).
2. You haven't told us the design heating load or the design cooling load.
3. You haven't told us what you mean by a "traditional HVAC system" -- although I can guess. (You're probably talking about either a furnace plus a split system air conditioner, hooked up to a forced-air distribution system, or an air-source heat pump hooked up to a forced-air distribution system.)
4. You haven't told us what type of equipment is included in each bid, or the equipment rating.
Without heating & cooling load calculations (on a room-by-room basis) it's impossible to zoom in on the optimal solutions.
A $12K quote for a mini-split system sounds like there are 3-4 zones / heads / cassettes. (?), which would usually be extreme overkill for the actual loads. It's likely that it only needs between 0.75-1.5 tons of compressor to cover both heating & cooling loads for the whole house, but how that gets distributed may make a difference in comfort.
The $5K system probably includes ducts in the attic, above the insulation? If yes, that adds considerably to the actual load (and the actual energy use), no matter how well insulated the house is.